1. Field of the Invention
The present invention relates to an image display apparatus and an image display method, which are used for displaying an image based on image data received typically from an image supplier.
2. Description of the Related Art
There has been provided a standard named a DDC (Display Data Channel) standard as a standard, which should be called a plug-and-play for an image display apparatus. In accordance with the DDC standard, information on attributes of the image display apparatus is supplied by the image display apparatus to a host, which is an apparatus supplying an image signal, and the host automatically does setting adjusted to the characteristics of the image display apparatus. An example of the attributes of the image display apparatus is an optimum resolution.
In accordance with the DDC standard, information on characteristics of the image display apparatus is supplied by the image display apparatus to a host in the form of data having a format called an EDID (Extended Display Identification Data) format. Even with the power supply of the image display apparatus turned off, the host supplies power to the image display apparatus so that the image display apparatus is capable of transmitting the EDID data to the host. It is thus necessary to store the EDID data in a nonvolatile memory such as an EEPROM in order to prevent the EDID data from being lost even if the power supply of the image display apparatus is turned off.
In the past, an image output apparatus conforming to the DDC standard was computers only. The types of resolution of an RGB signals output by the computer are VGA (640×480), SVGA (800×600), XGA (1280×768), SXGA (1280×1024) and QXGA (2048×1536). Thus, for example, the EDID data stored in the nonvolatile memory of the conventional image display apparatus conforming to the DDC standard as data related to the resolution is a recommendation saying that SVGA is the optimum type of resolution for the RGB signals.
In addition, there has been proposed a display system in which, when an image output by a personal computer is displayed on a display unit, a technique of transmitting the data of the received image and the attributes of the image such as the resolution and frame rate of the image are identified by carrying out a format conversion process, and the data of the image is processed in accordance with the technique and the characteristics. If the technique of transmitting the data of the image received and the attributes of the image are not appropriate, the personal computer is requested to retransmit the EDID data. For more information on the proposed display system, refer to information sources such as paragraph [0041] and FIG. 1, which are included in Japanese Patent Laid-open No. 2001-265313. This document is taken as Patent Document 1.